Autonomous working machines in road construction 4.0: ROBOT

Road construction works - especially maintenance - that are done at partial closure mean a high risk for staff. Because working close to rolling traffic implements a high risk for people on construction sites, for example, for operating personnel at the paving screed.

          
 
Yet, it is not only a higher risk for accidents, but there are several factors that staff at road construction sites calculate: For example, dust, vibration, and noise are stressful factors.

To change that, the project “ROBOT – Road Construction 4.0 – Autonomously working machines in road construction” aims to minimize risks and improve safety as well as quality of road surfaces on construction sites.
MOBA is one of the cooperation partners of this forward-looking project that researches potential improvements through autonomous working construction machines, digitalization, and connection of machines.

Machine automation: Status quo

Nowadays it is already usual that single functionalities for example on pavers, rollers or milling machines are automatically controlled and regulated. But until now, all these machines and working steps are not interconnected with the others, and many different functionalities must be set and adjusted manually, so that the operational staff has to be close to the machine – which means directly in the machine’s and the construction site’s danger zone.

Connecting information and machines

To improve construction processes and safety, it is not enough to have single functions of construction machines automated. Rather all the functionalities and the machines must be interconnected to build one single system. This means a huge range of sensors and actors must be connected in one system to allow an information exchange and a trouble-free high-quality process of road construction.
By the help of the latest machine control technologies as well as sensor and IT-systems construction machines can be connected to each other and can be automated up to a degree that they are working autonomously, so that only the machine driver must be on the machine, but no further operational personnel. Also, a continuous quality control can be realized by using modern technologies.

What you need: A 3D model of the project and communication

Necessary for an automated and connected construction process is a 3D model of the construction project. This model builds the target values.
The sensors that are mounted on the construction machines collect the actual status of the surface as well as the positions of machines. This data is collected and connected via an information system which uses the information to control the actuators in a way that the result corresponds to the 3D model.
The primary controller processes not only all construction site and paving data but also the simulation in real time. The incoming data for the simulation model are the machines reference values. The simulation visualizes a result tendency for the working process. With this visualization differences can be detected, and countermeasures can be taken early.
                                       

ROBOT connects road construction machines through the internet – this also allows the continuous collection and storage of relevant data like for example temperature of mixture, paving width and thickness or compaction in one single information database. This data and its analyzation help to improve construction processes a lot.

Important factor: Compaction

The communication between the rollers helps to improve the compaction process.
The measurement of the surface is done by rollers that are wirelessly connected to each other and the primary controller. This way, all compacting data like number of passes, the compaction degree and the machine position are sent to the controller. The controller generates the reference variables for the machines working functions according to the difference between the 3D target data and the current state that is recorded by the sensors on the machines.
As all information is processed in one controller and shared with each roller, precise work results can be achieved.

Gapless chain from mixing plant up to rollers

Yet, ROBOT not only wants to connect the pavers and rollers, but it aims for a complete, gapless chain from the mixing plant up to the rollers. That is why besides the working machines also the asphalt mixers and the trucks that deliver the asphalt are integrated into the system, so that all information, for example the temperature of the asphalt, which plays an important role for the quality of the road, can be processed.
                   

For an autonomous paving process, the material transfer from truck to feeder must be automated. The systems need to be connected to be able to send signals to detect position, direction, and distance. If feeder, paver, and trucks communicate, an automated docking system can be realized. This way the mixture can be poured to the feeder’s or paver’s silo without human interaction.

Altogether the implementation of such a system with machine connection and digitalization not only means a higher working safety, but also a higher paving quality and better paving results. That in turn results in an increased longevity and sustainability of roads. And for all traffic participants this means less construction sites, less traffic jams and higher safety on our streets.